I’m 40 years old, and nearly 8 years have passed since my last professional fight. After that bout ended in a draw, I spent the next few years going back and forth on whether I’d ever step into the ring again. But after doing a training camp with Roy Jones Jr. to help him prepare for his fight against Mike Tyson, I finally made up my mind: I would never fight professionally again. Or so I thought. After I got my book deal, I dove into the strategies behind successful books like David Gogg...